Unilateral, Sectoral Retinal Metastasis of Small-Cell Lung Cancer Mimicking Viral Retinitis.

Retinal metastases are exceedingly rare, particularly retinal metastasis of SCLC. Retinal metastasis should be considered in patients initially diagnosed with viral retinitis who fail to improve despite antiviral therapy, particularly if they have a known history of malignancy. Furthermore, retinal metastasis of SCLC potentially could be misdiagnosed histopathologically as retinoblastoma if the patient's history is unknown and appropriate immunohistochemical stains are not performed.